Nineteen NIH-funded investigators from seven departments in two colleges at Colorado State University are applying for $391,975 in DRR funds to purchase a JEM-2000 EX extended-range (200 kV) transmission electron microscope (TEM) and a Gatan Model 626 Cryostage. The JEM-2000 EX will replace two 22 year-old TEMs --an Hitachi HS-8 TEM and Philips EM-200. Conventional TEM and high voltage electron microscopy (HVEM) are currently used to examine labeled and unlabeled thin and thick sections, whole-mounts of critical-point-dried cells, conventional freeze-fracture replicas, and immunogold "labeled-replicas" in a wide variety of projects in anatomy and neurobiology, biochemistry, cell and molecular biology, development biology, microbiology, pathology, and virology. The increased accelerating voltage and great depth of field available in this new generation of 200 kV TEMs will significantly improve current imaging capabilities and reduce the need to travel to the national HVEM facility in Boulder, CO. An integrated TV camera and image intensifier linking the JEM-2000 EX to an existing Ke Vex Super 8000 image analysis system will be used to: a) preview beam- sensitive samples at very low electron fluxes, b) compare successive regions in serial sections before photography, c) simplify overlapping of adjacent images during montaging, d) permit preliminary digital analysis of TEM images, and e) allow prolonged viewing and discussion of stored images without further damage to specimens. The cryostage will permit frozen hydrated cryosections to be examined on an existing Philips 400T TEM/STEM/X-ray microanalytical system. With the decommissioning of the two decrepit TEMs, the 10-year old Philips 400T will be the only TEM remaining in the CSU EM Center. Since it was purchased from state funds dedicated for teaching, it will not be routinely available for our use for five months each year. More important, it is permanently configured for materials science research (i.e., short-focal-length, low-contrast objective lens, STEM and EDS). Thus, even when available, it is not suitable for the primary needs of the researchers in this group. Within 6- 12 months, the JEM-2000 EX will become crucial to the completion of many of the NIH-funded projects. The JEM-2000 EX will be installed in a vacant TEM suite in the 4,370 sp.ft. CSU Electron Microscopy Center located in the basement of the Anatomy- Zoology Building. To pay for service contracts and operational expenses, uniform hourly use fees are assessed on all equipment. Appropriate administrative and technical personnel (2.20 permanent employees), as well as an established EM Center Board of Directors, will ensure efficient scheduling and continued successful operation of the requested JEM-2000 EX transmission electron microscope and Gatan 626 cryotransfer system.